Treatment of hydrocarbons



. unitary Patented on. e, Y1946 Y TREATMENT F HYDEocARoNs Robert E.Burk, Cleveland Heights, Ohio, assignor to The Standard Oil Company,

Cleveland,

Ohio, a corporation of Ohio Application June 22, 1943, Serial No.491,755 s claims. (ol. 26o- 671) This invention relates to the treatmentof hydrocarbon stocks to form alkyl aromatics such as ethyl benzene andiso-propyl benzene, and also branched chain aliphatics such asiso-hexanes, iso-heptanes, and iso-octanes, all of which are valuablefor use as an aviation gasoline base stock, with lead tetraethyl, orblended vwith other stocks or in ratios other than those of normalrecovery. f

More particularly, the invention comprises a process in whichhydrocarbons are cracked so as to form an ethylene and propylenecontaining fraction, an aromatic containing fraction, and a butane andpentane containing fraction; and the first fraction combined with thelatter two fractions through appropriate alkylation and isomerizationand alkylation procedures, respectively.

It is an object of the invention to provide a unitary process foralkylating aromatics and (isomerized) aliphatics formed 'inv the samecracking process-by means of olens also formed in said cracking process,so as to utilize a substantial portionof the hydrocarbons formed incracking to provide products of the greatest value for motor fuelpurposes. A further object of the invention isfto provide aprocess inwhich essentially the same catalytic material may be used for theisomerization and both of the alkylations, and which material comprisesessentially hydrogen fluoride and boron trifluoride. i

Still a further object of the invention is the provision of a process inwhich the catalyst used in theisomerizing and `alkylating is notdeleteriously affected by the products of the cracking operation, andwhich catalyst can be recovered continuously andreused in theisomerization and either or both of the alkylations.

A An additional object of the invention is the provision of a processin'which the catalyst used in one alkylation may be transferred to andused in the other alkylation before separation of the catalyst from theoff-gas.

` Still a further object of the invention is to provide a process oigreat flexibility in which the oleiins may be used selectively foralkylating either the aromatics or the iso-paraiiins, i. e., theethylene may be reacted with the aromatics and the prcpylene with theiso-parafns, or the ethylene reacted with the iso-paralns and thepropylene with the aromatics, or in which both olens may be reacted withboth the aromatics and iso-parafiins. f

. 'A further object of the invention is the provil diately quenched withwater sion of a process in which a single catalyst recovery system maybe used for the isomerization and both the alkylation processes toseparate the catalyst from the off-gas and make it available i or reuse.

Other objects of the invention will be apparent from the followingdescription of an illustrative example which is to be read in connectionwith the sheet of drawings forming a part of the specification.

The cracking and separation of cracked products the invention, acracking drastic cracking, i. e., a high temperature for a relativelyshort time. The stock may vary from the lower gasoline range to thekerosene range, although different stocks will yield somewhat differentproducts, and in different amounts when cracked, and the stock may beselectedl with this in View, The temperature may vary from about 1250 to1750 F., depending In accordance with stock is subjected to on thestock, the-cracking time, and the relative y amounts of the productswanted. The time may vary from about 0.1 to 0.25 seconds depending onthe stock, the temperature, and the relative amounts'of the productswanted. The pressure may vary from about atmospheric to about 300 poundsper square inch depending on the other variables noted above.

The stock is fed through an inlet I, to the which it is immeor oil inthe conduit 3, and fed to the tower 5. If the quench is oil it isremoved at 6 with any other condensate.

cracking furnace 2, following The vapor leaves the tower 5 through aconduit 1 and is subjected to a Water quench as it moves to the tower 8.The water is removed for the most part at 9.

The hydrocarbons formed in the cracking operation are fractionated inthe tower 8, the major portion of the gaseous products leaving the topat I0, where they are compressed by the pump II and sent to the towerI2, where the C3 and lighter hydrocarbons are removed from the top at I3asa gas and sent to the supply line I4. The C4 and heavier hydrocarbonsare removed from the tower 8 through the conduit I5 and sent to thetower I8 by the conduit I1. Any C4 and heavier hydrocarbons separated inthe tower I2 may be added at I6 and sent to the tower I8.

The tower I8 serves to separate the Ce and heavier hydrocarbons from theCs and lighter hydrocarbons. The Ce and heavier hydrocarbons are removedat I9, and the C5 and lighter hydrocarbons are sent to the tower 20where any remay be returned by adjusting the valves 21 andl 28, and sentto a separate cracking furnace perated at about 20 to 50 F. higher thanthe temperature of the furnace 2L forfur-ther cracking. The productsfrom thissecond' cracking furnace may be fractionated in the manner de'-scribed and the C5, C4 and lighter' hydrocarbons added to the respectivesupply lines 22, 26 and i4, The C5 and higher hydrocarbons are fed tothe supply line Z 9.

lint accordance with anillustrative example, the cracking stock: may bea heavy naphtha, i. e., a major portion boiling within. the range of 300to 450. F. The cracking temperature may be 1380 to 1650" E, the time ofcracking about 0.175 second and' the pressure about 5 pounds per squareinch. Such a cracking operation will pro.- duce products of about` thefollowing amounts:

Weight per cent onfeed Ethylene 17 to 23 Propylene 27 to 33 Butadiene 4to 9 Butylenes 3 to 7 Butanes 7 to 9 Pentanes 4 to 6 Benzene 7 to 13Toluene 3 to 5 Xylenes 2 to 4 The ethylene and prop-ylenel are fed intothe supply line t4, and to a suitableV gas holder Ma, from' which theymay be withdrawn and used in the a'lkylation processes tobe described.The C4 and'v C5 hydrocarbons are sent to their respective storage tanks35 and Si. If desired the fract-icnator 2i may be omitted and the C4 andC5 hydrocarbons treated as a single fraction and lsent to-a commonstorage tank.

The Cs and higher fraction contains a substantialV amount of benzene(C5), toluene (C1) and xylenes (Ca). This fraction is fed from thesupply line 29 tothe fractionator 52. Provision is also` made foraugmenting the supply of benzene or other a-romatics which may beadmitted through the valve 35;

The fractionator 52 preferably separates the benzene and toluene; theformer is sent through pipe 34 to a storage supply 35 and the latterthroughl pipe 36A to storage supply 37. If desired, the benzene andtoluene may be separated as a single fraction and sent to a commonstorage supply. The Xylenes and heavier aromatics are removedY from thebottom of the fractionator 32 and sent to a fractionatorv 38. Ifdesired, the toluene may be separated with the Xylenes and heavieraromatics. The fractionator 38 separates the wanted aromaticsgenerallythe Cs, C9 and Cio aromatics, such as Xylenes, ethyl benzene, iso-propylbenzene, ethyl methyl benzene, diethyl' benzene, methyl iso-propylbenzene, etc., and they are removed through the conduit 39 and sent tostorage 4d. The C7 hydrocarbons may be included in the wanted productsdepending on the operation of theV fractionators 32 and 38. The heavieralkylate is removed at lll and may be turned: to the further cracked,dealkylated or otherwise used or disposed of.

The amg/lation of aromatzcs 7 triiluoride.v

For illustrative purposes, it may be assumed that, the benzene is to bealkylated. Benzene is fed through conduit 42 to the aromatic alkylator432. rihe valve 44 is opened and the valve 45 is closed. The mixturecontaining ethylene and propylenerisv admitted to the alkylator 43through pipe- 46., The catalyst. is. admitted through the conduit 471,valve 48 and conduit 49. Since the propylene. is more reactive theyconditions may be adjusted' sov that only thev propylene will react andthe.I product formed Will. be primarily isopropyl benzene (cumene). Thisis removed at lfandY returned at 5| for fractionation so that thealkylate ends as one of the Wanted products in theY storage. 4l). Theamount of benzene in the alkylator 43A generally is in excess of thestoichiometric amount of propylene to be reacted, and` the unreactedbenzene may be recycled through the conduit 50, fractionated andrealkylating zone through conduits 34` and`42. The unreacted ethylene.and the catalyst are removed from the alkylator at 52. Valves 54, 51 and58a are closed andvalves- 53, 58- andY 58, are open sothat ethylene andthe catalyst passte the conduit 59 to be used in the alkylation ofisopara-fns to bel described later.

The olefin containing gas and the benzene may befed tov the alkylator43, concurrent, countercurrent or both;V Under the preferred conditionsthe. aromatic will be in the liquid phase and the catalyst and olefin inthe gaseous phase. However, all ofthe components may be in the vaporphaseor inY the liquid phase, depending primarily on the. temperatureandpressure of the operation. Ina vapor phase operation, thetemperature` of the reaction, under the preferred conditions, is abovethe boiling point of hydrogen fluoride atv the pressure used (671 F. atatmospheric. pressure-l, for example, within the range F., preferablyto- 150 F. In a liquid; phase operatiom the temperature would 13e-25m140 F.

The pressure mayA bef varied over a wide range, but under the otherconditionsv preferred a pressure of atmospheric to 25o" pounds per sq.in. pressure is; utilized. Under the preferred conditions the pressure.should below enough to permit the hydrogen fluoride catalyst to begaseous except for such as may bev dissolved inv the benf zene in the.liquidY phase'atthe temperature used.

The time; inwhich'; thereacti'on occurs will depend;upon the sizeof. thereacting vessel, and the rate and nature ofv the. flowA of. materialsthrough it. Under the preferred', conditions' the time ofreactiomiszvery shortfand is of' an order of from one-fth minute: tofifteen minutes, a time of from .20y to4300seconds being entirelysatisfactory. The catalyst-used in the process, as` mentionedpreviously, is hydrogen fluoride promotedy bya minor proportionv ofboron triiluoridel. The

or separately. However,

is collected inthe receiver 1I. fwill be gaseous boron I through valve65.

the vapor pressure of the hydrogen temperature of the isomerization.Boron fluoride l is dissolved in the liquefied hydrogen fluoride used-as the catalyst and the amount .dissolved depends amount of borontriuoridemay vary from a trace u'p to 50 mol per cent.- Large amountsofboron trifluoride are not required. .The amountofthe catalyst employedis Vnot critical except that a suflicient amount must be employed undertopermit the reaction pletion desired. Larger amounts permit ,shortertimes of reaction Aand corresponding alterations in temperature andpressure and give better yields. Under the conditions ofthe process itis preferred to employ the minimum amount that will achieve the desiredYcompleteness of the reaction. In general the amount will vary fromabout 2 to 50%, an amount of the order of about 4 to 15% is preferred.The ymol ratio of olefin to benzene may be about 1 m01 of olefin to 1 to8 mols of benzene, but the higher ratios are'preferred and the excessben-y Vzene is then recycled. f

VLAS a specific example, in which a propylene and ethylene containinggas is fed to the alkylator, and benzene is the aromatic to bealkylated, the reaction may be carried out at a temperature of 110 F.The contact time of the propylene and the benzene may be 35 seconds, thepressure may be 100 pounds per square inch. The amount of catalyst(hydrogen fluoride with a trace of boron triuoride) may be about 14%based on the benzene inthe reactor. The amounts of propylene and benzenemay be 0.66 and 7.21 pounds per hour, respectively, the mol ratio ofbenzene to propylene being about 5.9 to 1.0. Under these conditions theiso-propyl benzene formed is about "1.03 pounds per hour. 4--While inthe above examples benzene is described as the aromatic to be alkylated,toluene may be treated under the same conditions. If toluene isalkylated instead of benzene the product will be primarily methyliso-propyl benzene; if both benzene and toluene are alkylated together,both iso-propyl benzene and methyl isopropyl benzene will be formed asthe primary products. Y

The isomerization of paramns The n-butane and n-pentane in the storages-3I and 30 are isomerized to form iso-butane and iso-pentanes. These maybe isomerized together separately with facility because of thesimplicity of recycling the unisomerized fraction. For i1- lustrativepurposes, it may be assumed that the butane is to be isomerizedseparately. It is removed from the storage 3l and fed through a vconduit60 to an isomerizer B I. YCatalyst from the conduit 41 may be admittedthrough the valve 62a and conduit 63. A pump 63a may be included in theconduit 63 to place the catalyst under pres- The liquefied catalystAbove the liquid trifluoride under pressure. admitted to the isomerizerThe isomerization is carried out preferably w'th the catalyst in theliquid phase, that is, with liquefied hydrogen fluoride .containingboron trifluoride dissolved therein.

sure and liquefy the same.

The liquid catalyst is :This is accomplished by employing a temperaturefor the isomerization below the boiling point of the hydrogen fluorideat the pressure employed, or in other words, a pressure at least asgreat as fluoride at the they can be isomerized upon the partialpressure ofthe boron fluoride and the temperature. This may beincreased, if desired, by the pump 64a in the conduit 64 and the borontrifluoride admitted. through the valve.

- the mixture is transferred to a separator 62 in which the hydrocarbonsseparate as an upperV layer and the catalyst separates as a lower layer.

Generally, the stratification may be accomplishedV by settling, butcentrifuging or other separating techniques may be employed.

The lower catalyst layer (which may be an emulsion of catalyst andhydrocarbon) is withdrawn inthe conduit 63h and returned through theconduit 64b to the isomerizer 6I where it malr be reused. In this way itwill be apparent that large quantities of fresh catalyst are notlrequired, but such as `may be necessary can be admitted through thevalves E5 and 65a. If the lower layer builds up with hydrocarbons,particularly unsaturates which may form a complex with thecatalyst, aportion of the lower layer may -be withdrawn, the catalyst removedtherefrom by heating, and the catalyst returned to the conduit 4l on anyof the zones in which it is used.

The upper layer containing substantial portionsof iso-butane iswithdrawnfrom the separator 62 through the conduit 6B, and transferred .to thefractionator 61 in which the iso-butane is removed at the top andtransferred through the conduit 68 to the iso-paraffin alkylator 69. Then-butane not isomerized is withdrawn from the fractionator 61 by meansof the conduit 10 and returned to the isomerizer 6I through the conduit64b.

Provision is also made to admit an additional quantity of normal butanethrough the valve 12 if the amount obtained in the cracking process isnot sulclent to utilize all of the olefin formed during cracking. Y

As has been mentioned previously, the isomerization preferably iscarried out under suicient pressure to maintain the butane and thecatalyst in .the liquid phase at the isomerizing temperature employed.This pressure is preferably accomplished by utilizing relatively highpartial pressures of boron trifluoride and this partial pressure may befrom 25 up .to 550 pounds per square inch. Since the catalytic activityofthe catalyst depends in part upon the amount of boron triiluoride, theactivity may be controlled n perature, pressure, amount by regulatingthe partial pressure of the boron trifluoride. The amount of catalyst'used may vary depending upon the speed of the reaction desired; ingeneral, from 25 to 100 volume per cent of the catalyst based on thehydrocarbon is preferred. TheY temperature may vary from a relativelylow figure, for example, --25o F. up to 215 F. Higher temperatures,however, not only require increased pressure to maintain the liquidphase but also tend to undesirable cracking. The lengthl of time towhich the hydrocarbon is subjected to the isomerizing catalyst may varydepending upon the extent of isomerization desired in a single pass.Inasmuch as provision is made for recycling, it may be more eiiicient tocarry out the reaction for shorter periods accompanied by greaterrecycling; a period of from 15 minutes to 3 hours is preferred. l

It should also be understood that the temof catalyst, amount of lborontriuoride and .the time of treatment are more or less. interrelated' andthat any one vari.- ableshould be. selected and adjustedv with referenceto the others for the most encient operation. This consideration,however, goes only to eiliciency and yields and not operability and,therefore, may be adjusted by those skilled in the: art in. view of .thedescrption'herein.

As an illustrative example', n-butane may be subjected tothe catalytic'action of 50 volume per cent' of liquid'v hydrogen iluoride in which isdissolved' boron trifluoride in an amount as ,to provide a partialpressure ofA boron triuoride of 300' pounds per square. inch'.Isomerization may be carried on for two hours at a temperature of 122E'. The producty is found to contain about 27 per cent iso-butane.

The above processhas. been described particularly with reference to theisomerization of bu- .tane but it may be carriedout in the same way withpentane. In this event pentane is withdrawn. from storage 30 and treatedin the same manner as previously described.

If .the butano and pentane have not been separated. by a fractionatorsuch as shown at 2'I so the normal hydrocarbon for isomerization is amixture, or if it is desired to isomerize both the butane and pentanesimultaneously by withdrawing from both the storages 30 and 3|, .this:can also be accomplished in Ithe same manner described previously.Under such circumstances, however, it is desirable tov utilize anadditional fractionator .to separate the: iso-butane and isopentane fromthe normal butane and, normal pentane after isomerizationso that both of.the unisornerized, normal hydrocarbons may be returnedthrough. theconduit 'lll for further isomerization.

Allcylatzon of iso-butano and/or iso-pedirme The iso-parafns isomerizedin the manner" described previously are. then. alkylated with. anolefin. In the following illustrative. example it is assumed that then-butane has been i'somerized separately and that the iso-butane4 willbe. alkylated separately. The iso-butane coming. from the fra'ctionator6l is introduced into the. alkyl'- ator 69 through the conduit. 63.Inasmuch as the alkylaton preferably is carried' out 'm the liquid.phase, the catalyst may be introduced in the liquid phasefrom. thereceiver Il through. the valve T3. The olefin used for the alkylation.in this example is. the ethylene and catalyst containing gas left overfrom. the alkylation of. the aromatics, and which. existsy from. the.aromatic alkylator 43 through conduit 52 and valves: 53.-, 56, 58 andconduit 59. A. pump 'I5 maybe. provided to liquefy .the hydrogenfluoride and place the boron fluoride under the propel' pressure". Sincein the illustrative example the propylene will have been used inrallrylatingY thearomatics, the product formed in the alkylation ofiso-butane with the remaining ethylene. will? be the isomeric hexanes.

The alkylation is accomplished by mixing the iso-butano withV thecatalyst in'. the liquid phase in the presence of the olen; after'thereaction has proceeded to the desired extent, the mixture is transferredto ythe separator 1S wherev the hydrocarbon and catalyst are separatedpreferably by gravity straticati'on. The separa-tedA catalyst layer(which may be a hydrocarbon-catalyst emulsion) may be returned' throughthe conduit "I7 to .the alkylat'or 69 and reused. In this way relativelysmall amounts of fresh catalyst are required from the supply 1|, If the'catalyst layer builds uptoo muchl in the form. off acatalysthydrocarbon complex, a portion. may be withdrawn and thecatalyst removedz therefrom. by heating and' the catalyst returned .tothe conduit 't1 or any of the zones utilizing the catalyst..

The upperV layer containing the alkylated products is withdrawn from theseparator 'I6 through a conduit 'I3 and transferred to the fra'ctionator19". The'alkylated products are-separated at the bottom of thefractionator through a. conduit and sentito storage.v Since the amountof iso-butaneused preferably exceeds the amount stoichiometricallyrequired; for reaction withA olens. provision. is made for recyling theexcess iso-butane through the conduit. 8l tothe alkylator 69.

The butano fraction in the storage. 3 I' alsomay contain butylenes, andif so, these may alkylate with the iso-butano in the isomerizer 6l..Provision is made for withdrawing such alkylates. at the bottom of thefractionator 61- through the conduit 82 and transferring them throughthe conduit lliV where they are separated with the wantedalkylatedproductsr in the conduit 80.

The alkylation reaction preferably should be carried out with an excessof the. iso-paran to promote complete utilization of. the olen andrepress polymerization thereof. In. general, the mol. ratioy of olen toiso-paran should be 1:2 to 12. The pressure should be sufcient tomaintain the isobutane and the catalyst inthe liquid phase. This may beaccomplished preferably by employing a relatively high partial pressureof boron triiluoride. The temperature. may vary from 30 up to 160 F. Ingeneral, thetemperature and partial. pressure of boron trifiuoridein thealkylation zone aret lower than in the isomerization zone. Thissuggestsy thatV the pump I4 may be omitted and the pressure in thesupply li maintained at that desired in the alkylation. Any higherpressure for isomerization can be supplied by the pump 64a.. The lengthof, the reaction may vary from 15 minutes. to. 3 hours but thealkylation may be accomplished in somewhat shorter time than theisomerization. The amount of the catalyst may varyy from l0 to 100volume per cent depending upon theY speed of the reaction. desired,temperature', and pressure. It is preferred to carryl out the'alkylation with a large amount of hydrogen fluoride and asmall amount ofboron `triiluoride or a large amount of boron fluoride. and' a smallamount of. hydrogen iiuoride..

The amount of boron tri-fluoride dissolved in the liquid hydrogeniiuoride depends on the pressure' and temperature andV may be expressedin terms of its partialpressure at a given temperature. The amount of.the catalyst' the proportiony of the twovv luorides, the temperature'and time. of the' reaction are morel or less' interrelatedi andY shouldbe adjusted with referencey to each other. These adjustments areyconcerned more with efciency and yields than with operability and maybey adjusted by' one skilled in the. art for the: most efci'en-toperation in view of the dis.- closures herein.

AS an illustrative example, iso-butano and ethylene. in the' proportionof about 1:0.7 mols may be reacted atv 40 F. for 1% hours in thepresence of liquid hydrogen fluoride. inl the amount of 50 vol. percentof the iso-butano and an amount of boron. triuoride to provide apartial'pressure of lpoundsper. square inch; Conversion tolabout 60% in the.`gasoline. range is obtainedl The gasolinev contains: about 25% isomayiso-hexanes and iso-heptanes. boiling below 350 F.

The above example has been described utilizing isoLbutane. The processmay be carriedl out under about the same conditions utilizingisopentane. For example, iso-pentane and ethylene be introduced into thealkylator E9 in the ratio of about 1:0.4 mols at 40 F. for 11/2 hours in-the presence of 60 weight per centhydrogen uoride and an amount ofboron trifluoride to provide a partial pressure of 50 pounds per squareinch. TheA yield shows a conversion of about 76%. About 30% isiso-butane which is recycled for alkylation, about iso-hexanes, about17% iso-heptanes, about 10% iso-'octanes and 19% higher products, mostof which are nwithin lthe gasoline range." Ii" desired a pentane may be`alkylated thesame conditions.

' Recovery of the catalyst pentanes, 36 the remainder mixture of.iso-butane" and iso together under about 'Ihe catalyst carried into thefractionator 19 with the hydrocarbon layer from the separator 16 islremoved at thetop of the fractionator 19 through Vthe conduit 83togetherwith unreacted gases, such as C1 toCs saturates and any smallamount of unreacted oleiins.. In the illustrativo example valves54 and 51 are closed, valve `E55 is open so that the catalyst is sent to anabsorber 84through the conduit 8,5. The absorber may be .a packed columnor bubble -plate column The absorbent ifs-introduced as a liquid intothe top of the absorber 84 by meansofa conduit 85a. The catalyst isabsorbed by or forms a loose chemical combination with theV absorbentand is removed through the conduit 8B. Any saturated C1 toACahydrocarbons in thesupplyl line I4 v .whichhavebeen carried throughthealkylators 43 and 69, after the catalyst .has been extracted therefrom,exit as the oir-gas in conduit-81 land may be used as fuel or for otherpurposes `deypending upon the composition therein. e The `absorbentcharged with the catalyst and removed through the conduit86 is sent to adesorber 88 where the catalyst is removed, and sent through conduit 44|Vfor use inthe isornerizing or either of the alkylating reactions. Thedenuded a)'r sorbe'nt is returned through the conduit 85a Ito theabsorber 84.r Y Y g The absorbent for separating the catalyst from thegas may beanyv'of a large -enumber of compounds which form acomplexwithor otherwise absorb hydrogen" fluoride and, borontriiluoride..`

Hv`IElXarnples are dihydroxyiluobcric acid; substituted `andunsubstituteddiarylketones, such as beuzphenone.. amines, clic.-compounds, and other nitrogenous basic compounds suchwas, diphenylamine,`coal tar bases, and chlorinated amines; certain aromatic ,hydro--carbfms,l ethers such as anisole `anddiphenyl ether; 'and certain metalfluorides. The temperature-under; which they absorption operation is4carried out will depend upon the absorbent used .and -the g, pressure.conditions maintained Vand is basic nitrogen-.heterocy- .such as tosecure a desirable or maximum absorpl tion.` When benzophenone is theabsorbenta `teniperature;from"near the melting pointoi `the.benzophenone up to 300511'. may be used,v preferably 160 to 210 F; Thedesorbing may be ac- ,complished `at a higher temperature at-which thecomplex is destroyed at least to some extent to i'reethe catalyst inthevapor form. In the case `oi'fbenzophenone a temperature within therange 2010300 to 530 F: may .bei used for desorption.

. The products leave racteristicsof theY wanted products,

'Alternative procedures In the examples described heretoforethevpropylene isused to alkylate the aromatics,and the ethylene isutilized to alkylate the iso-lparafns. If desired, this procedure may bereversed by closing valves 44, 53, 55,-and 58 and opening valves 45, 54,56, 51 and 58a. I

In this operation the propylene and ethylene containing supply in theline I4 is sent through the open valve 45 to the alkylator 69. Thepropylene being the more `reactive will be utilized to -alkylate theisofbutane and/or iso-pentane. The catalyst andunreacted ethylene willexit through the conduit 83, open valves 5l, 56; and 58a,.through theconduit 89, so that the aromatic alkylation is accomplished with theethylene and catalyst contained therein which is admitted through theconduit 89. In this procedure it may or may not be necessary to admitadditional catalyst through the valve 48 depending on the amount desiredwith the aromatic alkylation. the aromatic alkylator through conduit 52whichvwill containthe saturatedgases and the catalyst which will be sentthroughrvalve 54, conduit and the catalyst will be absorbed and desorbedin the absorber 84 and desorber 88, respectively. In this operation theiso-paraiiins`V alkylated withy the propylene will have a slightlyhigher molecular weight.v For example, if iso-butane is alkylated withpropylene the product will consist primarily of isomeric heptanes,'suchas'2,2l,3trimethyl butane. The product formed in the alkylation of thearomatics will be primarily ethyl benzene.

'Additional alternative procedures' r If desired, both valves 44 and 45may be opened and the mixture of ethylene and propylene fed to bothofthe alkylation zones. 'Ihe alkylation in each zone may be suiiicientlyvigorous to re-. act both the propylene and ethylene in each zone sothat the products exiting through the conduits 52 and 83 contain nothingbut the saturated gases and catalyst. In this event, valves 53 and 51are closed, valves 54 and 55are opened so that the catalyst from bothalkylators is sent tothe ab-v sorber 84. Si. IIt, willbe apparentin view-of theabove description that'the process is `extremely flexible in themode of operation andthe productsto be obtained. In.- general, themanneriny which the process is operated will depend uponthecharv themehrer iniwhichthe alkylated aromatics and alkylated isofparains are tobe blended either together or separately for products ofhigh anti-knockgaso-A line. l

The process has the additional advantage in that a singlecatalyst may beused for both isomerization and alkylation reactions and maybecontinuously reused and recycled through the various zones depending onthe relative 'requirements of each.

The process has stantially all of the the advantage of utilizing sub.useful products of the vcracking to form highly desirable finalproducts. In general, the cracking may be conducted'so` that the,proportion of the aromatics and aliphatics to be isomerized and/oralkylated maywcorre-,- spond. stoichiometrically with the oleflns formedby cracking and to be used in the alkylation processes. v l

It will be understood that the description of the invention isillustrative of a process and that the drawing is to facilitate anunderstanding of the process. It is not intended to show apparatuseither in form or scale that is necessarily suitable for practicing theinvention. Similarly lno attempt is made to include all of the heaters,condensers, pumps and other apparatus that may be necessary, as all ofthese features will be apparent to one skilled in the art in View of'lthe explanation of the process herein. c

The invention is capable of many modincations in the details ofoperation, as will be apparent to one skilled in the art, and all suchmodications are to be included as arewithin the scope of the followingclaims.

Iclaim: Y

1. The process which comprises heating hydrocarbons to a relatively hightemperature lfor a short time to form ethylene and propylene,- C4 and Caliphatic Ahydrocarbons, and aromatics, separating Athe C3 and lighterhydrocarbons containing propylene and ethylene, an aliphatic fractionselected from the group consisting of C4 hydrocarbons, C5 hydrocarbonsand a mixture thereof and comprising a normal parainic hydrocarbon, anda Cs and heavier hydrocarbon fraction containing aromatics; introducingthe propylene and ethylene containing fraction and the aromatics into analkylation zone and reacting the propylene with at least a part of thearomatics, isomerizing at least part of the normal parainic hydrocarbonin the aliphatic fraction, transferring the ethylene from the iirstalkylation zone and alkylating the isomerized hydrocarbon with theethylene.

2. A process in accordance with claim 1 in which the isomerization andboth alkylations are carried out in the presence of a catalystcomprising hydrogen fluoride and boron triuoride.

3. The process which comprises heating hydrocarbons to a relatively hightemperature for a short time to form ethylene and propylene, C4 and C5aliphatic hydrocarbons, and aromatics, separating the C3 and lighterhydrocarbons containing propylene and ethyleneJ an aliphatic fractionselected from vthe group consisting of C4 hydrocarbons, C5 hydrocarbonsand a mixture thereof and comprising a normal parafnic hydrocarbon, anda Cs and heavier hydrocarbon fraction containing aromatics, isomerizingat least part of the normal parainic hydrocarbon in the aliphatic`fraction, introducing the propylene and ethylene containing fractionand the isomerized hydrocarbon into an alkylating zone, and alkylatingthe isomerized hydrocarbon with the propylene contained in thelighterwfraction, transferring the unreacted ethylene and introducing itand at least part of the aromatics into a second alkylation zone andalkylating said aromatics with the ethylene.

4. A process in accordance with claim 3 in which the isomerization andboth alkylations are carried out in the presence of a catalystcomprising hydrogen uoride and boron triiuoride.

5. The process which comprises heating a hydrocarbon stock boiling inthe gasoline-kerosene range to a temperature Within the range of about1250c to 1'750 for a time within the range of about 0.1 to 0.25 secondto crack said hydrocarbon stock and form ethylene and propylene,aliphatic hydrocarbons in the butane-pentane range, and aromatics,fractionating the products to yield a C3 and lighter hydrocarbonfraction containing propylene and ethylene, an aliphatic hydrocarbonfraction boiling in the butanepentane range and comprising a normalparainic hydrocarbon, and a C6 and heavier hydrocarbon fractioncontaining aromatics; intro- 5 ducing atleast part of the aromaticcontaining fraction and the lighter propylene and ethylene containingfraction into any alkylating zone and reacting the propylene with atleast a part of the aromatic in the presence of a catalyst com# prisinghydrogen fluoride and boron triiiuoride at a temperature of 80 to 210F'., and at .a pressure of up to 250 pounds per square inch but not morethan that necessary to maintain the catalyst in the vapor phase,Awithdrawing the unreacted ethylene in admixture with catalyst,isomerizing the Vnormal parafnic hydrocarbon in the aliphatic containingfraction-at a temperature of 30 F'. to 215 F. in the presence of acatalyst comprising liquid hydrogen uoride in which is dissolved borontriiluoride under a partial pressure of 50 to 550 pounds per squareinch, separating the isomer and transferring it to a second alkylationzone, introducing the unreacted ethylene and catalyst withdrawn from thefirst alkylation zone into the second alkylation zone, alkylating theisomer at a temperature of to 160A F. in the presence of liquid hydrogenfluoride containing dissolved boron' fluoride under a partial pressureof to 200 pounds per square inch, transferring Vthe funre'acted productsof the lighterfraction and catalyst contained in the same to a recoveryzone, separating the catalyst from the 'unreactedlighter products, andreturning the catalyst for reuse.

6. The process which comprises heating a heavy naphtha hydrocarbon stockto `a temperature within the range of about 1380 to 1650 F., for about0.175 second to crack .said hydrocarbon stock and form ethylene andpropylene, aliphatic hydrocarbons in the butane-pentane range, andaromatics, fractionating the products to yield a C3 and lighterhydrocarbon fraction containing propylene and ethylene,A an aliphatichydrocarbon fraction boiling inV the butane-pentane range 4'5 andcomprising a normal paraiiinic hydrocarbon,

and a Cs and heavier hydrocarbon vfraction containingaromaticsintroducing at least part of the aromatic containing fractionand the lighter propylene and ethylene containing vfraction into 50 analkylating zone and reacting the propylene with at least a part of thearomatic in the presence of a catalyst comprising hydrogen fluoride andboron triuoride'at a temperature of 90 to 150 and at a ypressurenofabout80 to 150 V pounds per square inch, withdrawing the unreac'tedethylene Iin admixture 'With catalyst, isomerizing the normal parafinichydrocarbon in the' aliphatic containing fraction at a temperature of 65to 160 in thepresence of a catalyst comprising 25 to 100 volume per centliquid hydrogen fluoride (based on rthe hydrocarbon) in which isdissolved boron trifiuoride under a partial pressure of 150 to 350pounds per square inch, separating the isomer andtran'sferring it to asecond alkylation zone, introducing the unreacted ethylene and catalystWithdrawn from the 'rst alkylation zone' into the second alkylationzone, the isomer being stoichiometrically in excess of the ethylene,alkylating the isomer at a temperature of 10v to 105 F.

in' thepresence of liquid hydrogenuoride containing dissolved .boronfluoride under a partial pressure of 50 to 200 'pounds per square inch,recycling the unreacted' isomer, @withdrawing the alkylated products,"transferring the unreacted products of the lighter fraction and catalystcontained in the same and contacting them with an absorbent, desorbingthe catalyst from the absorbent, and returning the catalyst; for reuse.

'7. The process which comprises heating a hydrocarbon stock boiling inthe gasoline-kerosene range to a temperature within the range of about1250 to 1750 F., for a time within the range of about 0.1 to 0.25 secondto crack said hydrocarbon stock and form ethylene and propylene,aliphatic hydrocarbons in the butane-pentane range, and aromatics,fractionating the products to yield a Cs and lighter hydrocarbonfraction containing propylene and ethylene, an aliphatic hydrocarbonfraction boiling in the butane-pentane range and comprising a normalparailnic hydrocarbon, and a Ce and heavier hydrocarbon fractioncontaining aromatics; isomerizing the normal parainic hydrocarbon in thealiphatic containing fraction at a temperature of 30 F. to 215 F. inythe presence of a catalyst comprising liquid hydrogen iiuoride in whichis dissolved boron trifluoride and under a partial pressure of 50 to 550pounds per square inch, separating the isomer and transferring it to analkylation zone, transferring the lighter ethylene and propylenecontaining fraction to the alkylation zone and reacting the propyleneand at least part of the isomer at a temperature of -30 to 160 F. in thepresence of liquid hydrogen fluoride containing dissolved boron uorideunder a partial pressure of boron trifluoride of 50 to 200 pounds persquare inch, withdrawing the unreacted ethylene in admixture with anycatalyst, introducing at least part of the aromatic containing fractionand the withdrawn ethylene and catalyst into a second alkylating zone,and reacting the ethylene with at least a part of the aromatic in thepresence of a catalyst comprising hydrogen fluoride and boron.trifluoride at a temperature of 80 to 210 F., and at a square inch, butnot more than that which will maintain the catalyst in the vapor phase,Withdrawing the unreacted products of the lighter fraction and catalystfrom zone, separating the catalyst from the unreacted lighter products,and'returning the catalyst for reuse.

pressure up to 250 pounds per the second alkylating 8. The process whichcomprises heating a heavy naphtha hydrocarbon stock to a temperaturewithin the range of about 1380 to 1650 F., for a time Within the rangeof about 0.1 to 0.25 second to crack said hydrocarbon stock and formethylene and propylene, aliphatic hydrocarbons in the butane-pentanerange, and aromatics, fractionating the products to yield a C3 andlighter hydrocarbon fraction containing propylene and ethylene, analiphatic hydrocarbon fraction boiling in the butane-pentane range andcomprising a normal parainic hydrocarbon, and a Ce and heavierhydrocarbon fraction containing aromatics; isomerizing the normalparainic hydrocarbon in the aliphatic containing fraction at atemperature of -5 F. to 160 F. in the presence of a catalyst comprising25 to 100 volume per cent liquid hydrogen fluoride (based on thehydrocarbon) in which is dissolved boron trifluoride under a partialpressure of 150 to 350 pounds per square inch, separating the isomer andtransferring it to an alkylation zone, transferring the lighter ethyleneand propylene containing fraction to the alkylation zone and reactingthe propylene and at least part of the isomer at a temperature of +10 to110 F., in the presence of liquid hydrogen fluoride containing dissolvedboronfluoride under a partial pressure of boron trifluoride of to 200pounds per square inch, recycling the unreacted isomer, withdrawing thealkylated products, withdrawing the unreacted ethylene in admixture withany catalyst, introducing at least part of the aromatic containingfraction and the withdrawn ethylene and catalyst into a secondalkylating zone, and reacting the ethylene with at least a part of thearomatic in the presence of a catalyst comprising hydrogen fluoride andboron triuoride at a temperature of to 150 F., and at a pressure of 80to 150 pounds per square inch, withdrawing the unreacted products of thelighter fraction and catalyst from the second alkylation zone andcontacting them with an absorbent, desorbing the catalyst from theabsorbent, and returning the catalyst for reuse.

ROBERT E. BURK.

